Been thinking that it would be good if Canon did up grades. I have a EOS 1DMKII.

It's a very capable camera, but the pixel count of 8.2 is a bit low compared to more recent models. It's a shame Canon do not offer an up grade.

There have been talks of modular DSLR in the past.

I guess that DSLRs manufacturers are currently worried about their business model. They have created huge expectations since the move to digital with the rapid release of new models and the move to a computer like upgrade culture that helped their profits skyrock.

The problem being that the level of quality achieved by the current entrants is enough for most applications, and people are starting to upgrade less often.

A modular camera would most probably rfurther educe their profits from bodies and I am therefore not sure that they want to go there.

I imagine it might be a new sensor and a few other parts, but it would be cheaper than having to buy a complete new model.

You can always get a good part of your money back by selling your previous camera on eBay.

Upgrading the camera would probably require replacing most of the internals, since the higher resolution sensor would presumably require new electronics to process the increased data load without a decrease in speed. With labour costs it might well be less economical than selling the camera and buying a new one. It would probably also be wasteful, because they'd end up throwing the old parts away most of the time - the demand for spare parts can't be that high.